Any troubleshooting recomendations for cable internet?
I recently moved apartments and I'm leaving my beloved Google Fiber behind for some Spectrum cable internet that's included with the apartment (and I don't have any other choice). The issue is, it seems like I keep randomly losing connection and because I'm using my own router (but their modem) the Spectrum tech support hasn't been super helpful. For example, this morning I woke up and internet on my phone wasn't working, on my desktop I could ping stuff but it took ~20 seconds for the first packet to go through, but my router could ping things instantly. DNS was working if I got it from my router, but I have two PiHoles that I use for DNS with the router (running Unbound) as upstream. Rebooting the modem actually fixed it in that case, but I'll still have momentary drops here and there.
Anyone have any ideas of things to check? I've thought about going to Lowe's and buying one of those coax cable testers but I'm not really sure if that'd help much.
EDIT: For what it's worth, I live in Texas and there was a massive windstorm yesterday... and I think it's possible that that was the issue š¤¦āāļø I haven't definitely confirmed that, but it seems to be stable since the wind stopped and the wind did cause at least a couple of outages in the area.
Is it a modem/router combo? If so, then I would consider buying your own modem to remove another variable you don't have control over.
I have Spectrum and have my own Motorola/ARRIS Surfboard modem that I bought so I wouldn't have to deal with extra equipment I don't want/need with limited control.
Depending on your speed requirements, you might be able to get away with a SB6141 for a pretty reasonable price.
No, itās just the modem in this case. I actually had my own modem at first but itās been sitting in the trunk of my car for 2.5 years from the last time I had spectrum and I think that broke it xD
I might get a new one if I keep having issues with theirs
Make sure the modem is in bridge mode. Try disabling IPv6. Some of the Comcast backbones have weird IPv6 configuration which makes the connection unstable when it is enabled
I know this isn't the answer you want to hear but: try using all of the ISP's equipment to start. It will be somewhat annoying to set up their router, but if you use the same SSID/password all your equipment should be able to connect with minimum hassle.
If the connectivity problems go away, then the problem lies with your equipment's configuration. I'm unsure why you have two pi-holes, which makes me wonder if that may be part of the problem.
I was also going to come and suggest this, or something similar. In my experience dealing with cable companies for internet, you can at least take a machine and plug it directly into the modem or their router and go from there. If you have done this and can show connectivity problems the company is more likely to listen.
BYOM (bring your own modem) introduces another set of issues, in that I have had two separate cable companies refuse to troubleshoot anything when I had my own modem as it is "not their device" so you have to be careful on that front. No matter that the modem I had was explicitly listed on their page of approved modems.
Two pi-holes in case i need to reboot one, thatās all ĀÆ\_(ć)_/ĀÆ
(Read this with curiosity and not malice) how long does a reboot take? Why are you rebooting? Have you considered a docker deployment instead?
If these are actually on raspberry pi, are they getting cpu bound and stalling out dns?
Also does you router have logs?
I have one on an actual Raspberry Pi 4B and another instance running the OCI image of PiHole in an Incus set up on my NAS that's running Gentoo. In reality, I don't really need two instances because those are both pretty much running 24/7 and, if they're not, there's usually something else going on with my network (like a power outage or whatever). I really only reboot either the NAS or the Pi for kernel updates so not super often, but it's nice to know that, when I do reboot, I should still have DNS and my girlfriend won't yell at me lol.
I actually did only have the actual Raspberry Pi for far longer than I've had both instances, but I set up the second because why not. After my move, I did make sure to test
dig @<IPv4 & IPv6 of both instances> <various domains>to make sure everything was working again so I don't think that should be causing any issues.My router does have logs (I'm just running OpnSense) but I probably need to figure out more about how to read them. Also, I added this to an edit in the main post, but I think it's possible that a wind storm in the area was just causing some instability yesterday š¤¦āāļø everything has looked fine since the wind stopped and the wind did cause some local power outages that, in turn, caused some local Spectrum outages that could've been part of the issue.
If you don't mind that I probably won't be able to help much when it comes to the actual coaxial cable connection (I don't think those have existed in my country in quite a while), can you please clarify a few things about the problem? I gather you use your own router, not owned by the ISP, plugged in front of the modem that is owned by the ISP. Does the modem itself have any routing capabilities, or is your router responsible for managing its public IP address? (or is CGNAT in use?) If the modem has routing capabilities, are they on the same subnet?
It seems very strange that ISP-level issues could cause the router that you own, set up squarely within your LAN, to have a perfect connection and simultaneously other devices in your LAN to have a bad one.
I donāt think the modem has routing capabilities (they gave me a separate router which I just didnāt set up). Even if it does somehow, Iāve got my router set to use 10.124.15.0/24 so I donāt think itād overlap with the modemās subnet (if it did, thatād be super random).
I do agree that it seems strange that the router could have a working connection but not the rest of the network as a result of ISP-level issues, I just donāt really know what else it could be :p
Itās of course possible Iāve got some issues with my router configuration, but this is the same OPNsense config I was using before and it worked fine then and still works fine sometimes (most of the time?) at this new apartment. I suppose I could have an issue with one/some of the Ethernet cables between the router and the switch or the switch and other devices though, again, I was using these same cables at my old apartment just fine.
What's the brand and model of the router? Are you running original, modded or open source firmware? Can you run tests from the router itself?
When you say the internet isn't working, what other tests are you performing from the client devices to determine that - just trying to open websites and ping? Have you tried pinging a well-known IP address (rather than a domain name) during these downtimes from the client devices? For example
1.1.1.1. Can you ping from your phone?I'd definitely check for CGNAT or similar too. Are there private IP address ranges beyond the first hop (ie your router)?
I'm actually running OPNsense on some random AliExpress mini PC
Yeah, I've just tried to go to websites and use ping. Ping is the same even if I do it to an IP (well, I think I only checked 8.8.8.8 but still). I also tried
dig @<my pihole IPs> <whatever domain>and it timed out except for cached domains.I don't think there's CGNAT. I've got a 173.something/19 IP WAN address and port forwarding seems to work, i.e. I'm not home right now but I can access a couple sites I host at home on 443 to that WAN IP.
Can you ping around your network? Like you know that only outbound is the problem?
If it is, check your router logs during an outage.
As far as I can tell, yeah. I mean, I'm able to ssh to the router and also the my Raspberry Pi. I'll definitely check more of the router logs... though I probably need to look into more of what to check.
At a glance it seems you can SSH to opnsense. I'd try a non-ICMP test from the router, like with curl or something, during a downtime.
Other people's advice seems good too. I usually want to understand exactly what's happening in these situations but that's often not the fastest path to a solution.